The present invention relates to integrated circuits and semiconductor device fabrication and, more specifically, to structures for a non-volatile memory and methods for fabricating such structures.
Resistive random access memory (ReRAM) and magnetic random access memory (MRAM) provide embedded non-volatile memory technologies that contrast with other types of volatile memory technologies, such as static random access memory (SRAM) and dynamic random access memory (DRAM). Because ReRAM and MRAM memory elements are non-volatile, the stored content is retained when the memory elements are not powered, which contrasts with SRAM memory elements in which the stored content is eventually lost when unpowered and DRAM memory elements in which the stored content is lost if not periodically refreshed.
A non-volatile memory includes multiple active bitcells that are arranged in an array of rows and columns. Each active bitcell in the array includes a field-effect transistor that controls access to the non-volatile memory element for reading and writing binary data. A wordline is connected to the gates of the transistors in each row of the array. The wordline may be used to select the field-effect transistors in a particular row of active bitcells for data read and write operations to the related memory elements. Metal contacts may be used to contact each individual gate of the field-effect transistors in the given row of the array with their wordline. However, this inefficient connection scheme leads to overly-large active bitcell areas.
Improved structures for a non-volatile memory and methods for fabricating such structures are needed.